Electronics Forum | Fri Jan 19 06:52:36 EST 2001 | pteerink
We have had the same problem with several boards, and the problem was with the land pattern design on the PCB, not the stencil. We found that the part tends to center itself on the one large pad, and if the two smaller pads are not the right distance
Electronics Forum | Tue Sep 18 19:32:49 EDT 2007 | davef
Welcome Jimmy Let's mince words to help focus on the issues. When you say "QFP area solder paste shifted," do you mean: * Paste printed on land pattern perfectly, but moves after printing. * Paste printed off the land pattern, even though the stenci
Electronics Forum | Mon Dec 13 00:48:33 EST 1999 | armin
Hi All I have a 0.7 mm diameter hole for vias, what�s the minimum annular ring for this hole diameter? What�s the term unsupported and supported holes refer to in IPC-2221 9.1.2 Annular Ring Requirements? I have a proto-type PCB (designed by our R&
Electronics Forum | Thu Nov 07 10:59:11 EST 2002 | pjc
IPC-7525 "Stencil Design Guidelines" is a good reference document to have. Here are notes from a Tessera, (a major mBGA mfg.), study- "Application Note Solder Stencil Requirement for mBGA" The stencil aperture is to be square, equal in size to the l
Electronics Forum | Wed Sep 06 20:31:10 EDT 2000 | Dave F
Randy: My druthers on sources for SMT land patterns, in decreasing preference order are: 1 Manufacturers' recommendations. The problem with manfacturers' recommendations is that someone must make the effort to obtain them, document, and use them.
Electronics Forum | Fri Dec 15 11:23:23 EST 2000 | John
I searched the archives and couldn't find anything specific. Our designers would like me to wave solder an SO18 on an upcoming product. My IPC standards have land patterns, but no recommendation on wavesoldering. This is a higher pin count than we
Electronics Forum | Tue May 23 09:21:48 EDT 2000 | Brett W. Philipp
I am a PCB Designer / Mech. Engineer for a telecom company that has just started. What I would like, if possible is a reference copy of the SM-782A IPC spec. or some input on a way to calculate depending on the PLCC part dimensions, land pattern crea
Electronics Forum | Tue May 23 13:08:54 EDT 2000 | John Thorup
I second Wolfgang. Welcome, It's good to hear from someone who wants to design something we can build. Another useful resource is the land pattern book from SMT Plus www.smtplus.com 831/438-6116 Also useful are the component mechanicals available (fr
Electronics Forum | Mon Mar 20 20:22:47 EST 2000 | Dreamsniper
We used to have our PLCC,s, TSOP's and QFP's (0.65 mm pitch) Land Patterns designed in square corners. Some of our products have them designed in Full Radius Corners. As of now, with the two different designs running in our production floor, we can't
Electronics Forum | Thu Apr 09 00:07:54 EDT 1998 | Bonnie
I am in urgent need of a pcb land patten (footprint)for this device. I have the component data sheet with with package dimensions from Motorola, but they do not include the recommended land pattern. I requested a patten over a week ago, but have no
